MARTINEZ -- A 40-year-old woman was arrested Friday on suspicion of stealing a taxi in Martinez and driving the wrong way on Highway 4, causing multiple accidents, authorities said.

Police say the keys were inside the taxi at Marina Market on Escobar Street at 8:17 a.m. when Jaimee Ellam got inside and drove off.

Ellam got onto Highway 4, weaving eastbound through westbound traffic, according to California Highway Patrol spokesman Officer John Fransen. She first came upon a Honda Civic, which swerved off the highway near Morello Avenue to avoid a crash, Fransen said.

Next, a driver of a van swerved to the center divide to avoid the taxi, but an SUV behind the van clipped the cab, causing the SUV to flip over and crash into the van, Fransen said. Ellam then stopped the car, which was still facing east in westbound traffic, the CHP said.

She later was arrested on suspicion of car theft, Martinez police Sgt. Tyson Muncher said. The CHP said drugs may be a factor in the case. Two lanes of traffic were closed until 9:30 a.m. The extent of possible injuries was not known.

"The fact that there's no fatalities involved is fortunate," Fransen said.